Design method for small-f-number microlenses based on a finite thickness model in combination with the Yang-Gu phase-retrieval algorithm

Abstract

We present a fast and general iterative design method for both diffractive and nondiffractive two-dimensional optical elements. The method is based on a finite-thickness model in combination with the Yang-Gu phase-retrieval algorithm. A rigorous electromagnetic analysis (boundary element method) is used to appraise the designed results. We calculate the transverse-intensity distributions, diffraction efficiency, and spot size of the designed microlenses at the focusing plane for microlenses designed using the presented method and the conventional zero-thickness model. The main findings show the superiority of the presented method over the conventional method, especially for nondiffractive optical elements.

Diffractive micro-optical elements for implementing hollow beam and bi-focus simultaneously

“…A comparison of numerical results for designing and analyzing DMOEs by using the rigorous BEM, the scalar method (the first Rayleigh-Sommerfeld method), and the improved scalar method can be found in Refs. [31,32].…”

“…Instead, vectorical diffraction theory should be employed to analyze the DMOEs with sub-micrometer-sized structure [12]. Considerable investigations [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] into the design [22], the analysis [12][13][14][15][16][17][18][19][20][21][23][24][25][26][27][28][29][30][31][32], and the fabrication [33] of various DMOEs have been presented recently. In this paper, we design a diffractive micro-optical element with sub-micrometer-sized structure by introducing a half-p-phase shifting scheme to achieve bi-focus and hollow beam simultaneously.…”